Sitting in the front room of his suburban house in Delhi, Shri K. Subrahmanyam, the doyen of Indian strategic thinkers, sips some tea, coughs a little – and remembers the moment he decided that India must develop nuclear weapons. “It was on a visit to America in 1968,” he recalls. “I saw all the top strategic thinkers. Kissinger, who was still at Harvard at the time, Schelling; it was after that, that I decided we must have the bomb. As a matter of national survival.”